Each week our friends at Inhabitat recap the week's most interesting green developments and clean tech news for us -- it's the Week in Green.

Eco transportation took off this week as researchers in Sweden discovered a new molecule that could make rocket fuel 30 percent more efficient. We also caught up with Russia's plans to construct a new high-speed rail system for the 2018 World Cup, and we saw several major auto manufacturers give their vehicles green upgrades - Ford announced it will insulate its 2010 Focus with recycled jeans, and Chevrolet launched plans to transform 100,000 pounds of used oil booms into parts for the Volt.

Speaking of spreading renewable cheer, this month Japan's Enoshima Aquarium unveiled the world's first Christmas tree powered by an electric eel. The FAA also got into the holiday spirit as they approved a next-gen Santa sleigh that delivers gifts 53% faster, and if you unwrapped a new video game system this year, you may be interested to know that the Nintendo Wii was recently crowned the most energy-efficient next-gen gaming console. Finally, if the wintry weather has you feeling down, just take a peek inside this supermassive airship hangar, transformed into a year-round tropical island getaway.